a) voy/han cerrado (this is what I thought it was because I didn't think you could have "fui a..." as a form, but then it doesn't make sense because it goes from future tense to past)

Future tense... from a past perspective, not a present one: "Fui a" is still a past form (preterite, to be precise). Besides, the commercial stores had closed BEFORE you were going to go there, so there are no tense problems here. Even in English is the same:

I went there to buy, but the commercial stores had closed (already)

"Went to buy" refers to the future... from the past.

Oh, thanks so it's b)...

the options were:

a) voy/han cerrado (this is what I thought it was because I didn't think you could have "fui a..." as a form, but then it doesn't make sense because it goes from future tense to past)

b)fui/están cerrados

c)fui/habían cerrados

Anyone know the answer?

Thanks

No, he is saying it is c. When I went to buy [shopping], the stores** had** closed.

Hi qfreed,

Just one correction,

c)fui/habían cerrado[del]s[/del]

The stores are/were closed. (verb to be-estar)
Los almacenes están/estaban cerrados.
The stores are/were opened.
Los almacenes están/estaban abiertos.

The stores have/had closed (verb to have-haber)
Los almacenes han/habían cerrado.
The stores have/had opened.
Los almacenes han/habían abierto.

Hi qfreed,

Just one correction,

c)fui/habían cerrado[del]s[/del]

The stores are/were closed. (verb to be-estar)

Los almacenes están/estaban cerrados.

The stores are/were opened.

Los almacenes están/estaban abiertos.

The stores have/had closed (verb to have-haber)

Los almacenes han/habían cerrado.

The stores have/had opened.

Los almacenes han/habían abierto.

I got it. No <> as it is not an adjective here. Thank you very much.